Hydrocarbon vapor emissions may be released from an engine air induction system during certain engine conditions, such as an engine off condition. Hydrocarbon traps may adsorb the hydrocarbons during engine off conditions, thus reducing the release of the hydrocarbon vapor emissions. Upon engine operation, the hydrocarbons may be desorbed and drawn into the engine, thus purging the hydrocarbon traps.
The inventors herein have recognized various issues with the current hydrocarbon traps. For example, in some systems, the hydrocarbon traps may impede and/or disrupt air flow in the air induction system. Traps that impede a flow of air through the air induction system may decrease engine performance. Further, disruption of the air flow in the air induction system may result in inaccurate sensor readings, such as inaccurate mass air flow (MAF) readings. Moreover, many traps must be specially-designed for a specific air induction system increasing costs for designing and implementing an effective hydrocarbon trap. In addition, some operators may tamper with the hydrocarbon traps and evidence of tampering with the trap may be difficult to detect.
Accordingly, as a brief summary, devices, systems and methods are disclosed for a sleeve hydrocarbon trap. In one example, a sleeve hydrocarbon trap is provided including a hydrocarbon adsorbing sleeve and a cage to retain the sleeve. The hydrocarbon adsorbing sleeve may include one or more hydrocarbon adsorbing sheet layers. The sleeve hydrocarbon trap may be adapted to be disposed in a MAF bore such that a MAF sensor penetrates through the sleeve and the cage. The hydrocarbon adsorbing sleeve may substantially abut an inner wall of the MAF bore reducing air flow disruption and decreasing air flow restriction. Further, the disclosed hydrocarbon trap may be tamper resistant and may be easily adapted to a variety of different vehicle applications while utilizing existing packaging space.
It should be understood that the background and summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.